House - Mechanic Edition - Copycat Thread

[LuckyFlyingROUSH]

Saw the origional thread and though it was a good title...so I stole it.

Problem - At idle the car idles fine, but seems to have a slight miss or catch or something every so often. You can barely hear it, but its there. It doesn't run right if I slightly rev it up.

http://www.youtube.com/watch?v=5mhjPqIYSWI


Back story:
Got the new build back together, never touched the internals of the motor, just took off the supercharger and switched to turbo.

I started tuning it...which I am pretty rusty at. Adaptive learning is disabled. I got the Short fuel trims to hover right around 1 at idle, bank one is .03 lower than bank2.

Tightened all exhaust and sensors. Pulled the plugs, looked good. Gapped .28, checked all connections.

Maf counts hover around 155 idle..

Boost gauge stays around 20vac - Wideband hovers at 15.5 ish for some reason...I keep thinking that is exhaust piping related though.

Powerhouse Turbo - 80lb - P51 longblock - stock tb, HPX PMAS,

Any suggestions? I'm thinking pull the valve covers and check everything. If that checks out I am out of ideas.

I was planning on letting Lito have a go at the tune if I can't figure it out...but at this point I don't think its the tune and think its mechanical.

 

[retfr8flyr]

Sounds to me like it's running too lean. Did you get your transfer tables correct? It shouldn't be 15.5 at idle. The turbo setup is moving a lot more air at idle then that supercharger did. I would lock the tune in open loop and add fuel to get the idle AF down to about 13.5 ad see how it runs. If it still does the same thing then it would not be tune related.


Earl

 

[BruceH]

Is the hpx in a 3" tube?

 

[LuckyFlyingROUSH]

Built a completely new tune from the ground up. I think I may have an exhaust leak causing the wideband to say lean because the short term fuel trims say I am stoich. 14.7

 

[BruceH]

Built a completely new tune from the ground up. I think I may have an exhaust leak causing the wideband to say lean because the short term fuel trims say I am stoich. 14.7

Most likely that's the case. FYI E10 is 14.1

Edit: The wideband still shows 14.7 (1 lambda) as stoich no matter what the fuel is. Had a brain fart.

 

[LuckyFlyingROUSH]

I think 2.5 BA-5000 tables are the ones I used for MAF? I think the powerhouse kit was 2.5 at that point? The maf was relocated to a blow through setup a foot before it goes into the TB.

I guess I could load the 3.0 table and try again tomorrow...

 

[LuckyFlyingROUSH]

Added link to video of what its doin.